How to 'defrag' your computer and improve its speed when it's operating slower than usual

Most modern Windows operating systems will defrag your computer automatically, but you can do it manually if you have Windows ...
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6 signs your computer has been hacked – and what to do about it

Strange behaviour on your Windows or Mac PC could be more than a glitch, so check our tips to recognise the risks and keep your data safe With over a decade of experience at Which?, Tom covers ...